Incident Overview
A pilot reported hearing a loud bang when the landing gear was retracted. Subsequent attempts to extend the gear were unsuccessful. The pilot then burned off fuel, had the runway foamed, and executed a gear-up landing.
Maintenance History
During the most recent annual inspection, the landing gear actuator had been removed. The worm gear assembly and bearings were replaced at that time.
Post-Incident Findings
Examination after the incident found the landing gear actuator to be jammed. The spur and pinion washer (part number 105-090CR-032-4J) was not installed. Additionally, two bearing seal rings (part numbers NAS 50-125 and 35-810116) were missing. One of the seal rings, which was distorted, was discovered on the cabin floor near the landing gear handcrank.